Enhanced visible luminescence and modification in morphological properties of cadmium oxide nanoparticles induced by annealing

Cadmium oxide nanoparticles synthesised by a simple sol–gel synthesis method showed luminescence properties in the visible region of the electromagnetic spectrum. Both green and blue emissions were observed in photoluminescence spectra. We have investigated luminescence properties by changing the synthesis conditions. An enhanced luminescence of CdO nanoparticles was realised when these particles were annealed at different temperatures. Cadmium interstitial vacancies and oxygen vacancies played an important role in luminescence properties. X-ray diffraction confirmed annealing-induced changes in morphological properties. A good correlation between all the experimental results was obtained. Optical properties were investigated by diffuse reflectance spectra and photoluminescence spectra. Structural properties were investigated by high-resolution transmission electron microscopy.